Protection, excitation and synchronization cooperative control method and system under multiple working conditions

Abstract

The invention relates to a protection, excitation and synchronization cooperative control method and system under multiple working conditions, and belongs to the field of electric power protection control. The method comprises the steps that three-source parameters are integrated, the three-source parameters comprise a protection system parameter, an excitation system parameter and a synchronous system parameter, and a normalized state vector is obtained based on the three-source parameters; outputting a working condition characteristic matrix based on the normalized state vector and identifying a current dominant working condition; obtaining a control gain matrix, and outputting an optimized control vector through the normalized state vector and the working condition feature matrix; converting the optimization control vector into execution parameters and adding dynamic constraints, wherein the execution parameters comprise an excitation voltage set value, a negative sequence current threshold value and a compensation phase difference; and monitoring and feeding back the execution deviation in real time, and outputting a dynamic constraint coefficient for dynamically constraining the control gain matrix. According to the invention, protection, excitation and synchronous cooperative control under multiple working conditions are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of power protection control, and specifically relates to a coordinated control method and system for protection, excitation, and synchronization under multiple working conditions. Background Art

[0002] Coordinated control of protection, excitation, and synchronization devices in power systems is a core challenge in ensuring safe grid connection and stable operation of generators. Traditional technologies employ a "discrete design, localized linkage" model. The protection system relies on fixed thresholds, making it difficult to distinguish between faults and disturbances during transient conditions such as generator startup and sudden load changes, resulting in a high rate of false trips. The excitation system uses PID to track the generator-terminal voltage, but fails to account for grid voltage fluctuations and synchronization requirements, leading to excessive grid inrush currents. While the synchronization device incorporates a PID closed-loop phase adjustment, it responds laggingly to rapid frequency changes, resulting in prolonged grid connection times. In recent years, some improved solutions have attempted to exchange signals through hardwiring, but these solutions suffer from three fundamental flaws: parameter fragmentation: the parameters of the protection, excitation, and synchronization systems cannot be jointly analyzed, resulting in a fragmented system; operating condition rigidity: fixed control parameters are difficult to adapt to multiple operating conditions such as frequency fluctuations, faults, and grid connection; and dynamic mismatch: the lack of a coordinated error feedback mechanism can easily lead to oscillations. Summary of the Invention

[0003] In order to solve the above problems existing in the prior art, the present invention provides a method and system for coordinated control of protection, excitation and synchronization under multiple working conditions.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A method for coordinated control of protection, excitation, and synchronization under multiple operating conditions, wherein the implementation of the method for coordinated control of protection, excitation, and synchronization under multiple operating conditions comprises the following steps: S1: Integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters; S2: Outputting a working condition characteristic matrix based on the normalized state vector and identifying a current dominant working condition; S3: Obtain a control gain matrix, and output an optimized control vector through the normalized state vector and the operating condition characteristic matrix; S4: converting the optimized control vector into execution parameters and adding dynamic constraints, wherein the execution parameters include an excitation voltage set value, a negative sequence current threshold, and a compensation phase difference; S5: Real-time monitoring and feedback of execution deviations, and outputting dynamic constraint coefficients for dynamically constraining the control gain matrix.

[0005] Preferably, the step S1 specifically includes: Obtaining the protection system parameters, the excitation system parameters, and the synchronization system parameters, wherein the protection system parameters include the frequency change rate and the negative sequence current, the excitation system parameters include the grid voltage, the terminal voltage, and the voltage change rate, and the synchronization system parameters include the phase difference and the slip; The normalized state vector is output based on the three source parameters, which is mathematically described as ,in, is the normalized state vector, is the frequency change rate, is the maximum frequency change rate of the gas turbine, is the negative sequence current, is the rated current, is the grid voltage, is the terminal voltage, is the rated voltage, is the voltage change rate, is the maximum allowable voltage change rate, is the phase difference, To allow for grid-connected phase difference, is the slip weight, is the slip, is the maximum allowable slip.

[0006] Preferably, the step S2 specifically includes: Pre-training obtains weight matrix and feature vector; The working condition characteristic matrix is ​​output based on the normalized state vector, the weight matrix and the characteristic vector, which is mathematically described as: ,in, is the working condition characteristic matrix, is the weight matrix, is the eigenvector, is the steady-state probability, is the probability of frequency-varying operating conditions, is the probability of grid-connected operation, is the probability of fault condition; A current dominant operating condition is identified based on the operating condition characteristic matrix.

[0007] Preferably, the step S3 specifically includes: Determine the control gain matrix through multi-operating condition simulation optimization; Acquire an operating condition intensity coefficient based on the normalized state vector, the operating condition intensity coefficient including a frequency intensity coefficient, a voltage intensity coefficient, and a phase intensity coefficient; The optimized control vector is output based on the control gain matrix, the operating condition characteristic matrix and the operating condition intensity coefficient, which is mathematically described as follows: ,in, is the correction value of the excitation voltage setting value, is the protection action threshold correction coefficient, is the synchronous phase correction angle, is the control gain matrix, is the i-th row element of the working condition characteristic matrix, is the frequency intensity coefficient, is the voltage intensity coefficient, is the phase intensity coefficient.

[0008] Preferably, the step S4 specifically includes: The excitation voltage setting value is obtained based on the excitation voltage setting value correction amount, which is mathematically described as ,in, is the excitation voltage setting value, is the original excitation voltage setting value, To preset the grid connection time, is the current time; The negative sequence current threshold is obtained based on the protection action threshold correction coefficient, which is mathematically described as ,in, is the negative sequence current threshold; The compensated phase difference is obtained based on the synchronous phase correction angle, which is mathematically described as ,in, To compensate for the phase difference, is the original phase difference, is the attenuation factor.

[0009] Preferably, the step S5 specifically includes: Acquiring the execution deviation, where the execution deviation includes a voltage tracking error, a negative sequence current tracking error, and a phase difference tracking error; The dynamic constraint coefficient is output based on the execution deviation, which is mathematically described as ,in, is the dynamic constraint coefficient, is the voltage tracking error, is the negative sequence current tracking error, is the phase tracking error, is the voltage sensitivity coefficient; The control gain matrix is ​​dynamically updated based on the dynamic constraint coefficients, which is mathematically described as ,in, is the updated control gain matrix, This is element-wise multiplication.

[0010] A coordinated control system for protection, excitation, and synchronization under multiple operating conditions, used to implement the coordinated control method for protection, excitation, and synchronization under multiple operating conditions described above, comprising a data integration module, an operating condition identification module, a control optimization module, an execution module, and a dynamic constraint module; The data integration module is used to integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters; The operating condition identification module is used to output an operating condition characteristic matrix based on the normalized state vector and identify the current dominant operating condition; The control optimization module is used to obtain a control gain matrix and output an optimized control vector through the normalized state vector and the operating condition characteristic matrix; The execution module is used to convert the optimized control vector into execution parameters and add dynamic constraints, wherein the execution parameters include an excitation voltage set value, a negative sequence current threshold, and a compensation phase difference; The dynamic constraint module is used to monitor and feedback the execution deviation in real time, and output a dynamic constraint coefficient for dynamically constraining the control gain matrix.

[0011] The beneficial effects of the present invention are: (1) By normalizing the state vector, the key parameters of the three systems are integrated so that they can be optimized under the same mathematical framework, solving the "information island" problem of the traditional system.

[0012] (2) Collaborative control is carried out through the operating condition characteristic matrix to adapt to various operating conditions such as frequency change, fault, and grid connection, and collaborative control is carried out according to different operating conditions. It has strong adaptability and a wide range of applications.

[0013] (3) An error feedback coordination mechanism is established through dynamic constraint coefficients to monitor and control deviations during system operation in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0015] Figure 1 This is a flowchart of the steps of the coordinated control method of protection, excitation and synchronization under multiple working conditions of the present invention. DETAILED DESCRIPTION

[0016] In order to better understand the present invention, various aspects of the present invention will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present invention and are not intended to limit the scope of the present invention in any way. Throughout the specification, the expression "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, the terms "roughly", "approximately" and similar terms are used as terms to indicate approximate values, rather than as terms to indicate degree, and are intended to illustrate inherent deviations in measurements or calculated values ​​that will be recognized by those of ordinary skill in the art. In addition, in the present invention, the order in which the steps are described does not necessarily represent the order in which these processes occur in actual operation, unless otherwise specified or can be derived from the context.

[0017] It should also be understood that expressions such as "comprises," "including," "having," "includes," and / or "comprising" are open rather than closed expressions in this specification, indicating the presence of the stated features, elements, and / or components, but do not exclude the presence of one or more other features, elements, components, and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than just the individual elements in the list. In addition, when describing embodiments of the present invention, "may" is used to mean "one or more embodiments of the present invention." And, the term "exemplary" is intended to refer to an example or illustration.

[0018] Unless otherwise defined, all terms used herein (including engineering and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this invention pertains. It should also be understood that, unless otherwise expressly stated herein, words defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0019] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0020] Example 1: See also Figure 1 , a coordinated control method for protection, excitation, and synchronization under multiple working conditions, including: S1: Integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters; S2: Outputting a working condition characteristic matrix based on the normalized state vector and identifying a current dominant working condition; S3: Obtain a control gain matrix, and output an optimized control vector through the normalized state vector and the operating condition characteristic matrix; S4: converting the optimized control vector into execution parameters and adding dynamic constraints to achieve coordinated control of protection, excitation, and synchronization, wherein the execution parameters include an excitation voltage set value, a negative sequence current threshold, and a compensation phase difference; S5: Real-time monitoring and feedback of execution deviations, outputting dynamic constraint coefficients for dynamically constraining the control gain matrix in step S3.

[0021] In this embodiment, the normalized state vector is obtained based on the three-source parameters, which can be specifically implemented by the following steps: S101: Obtaining the protection system parameters, the excitation system parameters, and the synchronization system parameters through the protection system, the excitation system, and the synchronization system, respectively. The protection system parameters include the frequency change rate and the negative sequence current. The excitation system parameters include the grid voltage, the terminal voltage, and the voltage change rate. The synchronization system parameters include the phase difference and the slip. S102: Output the normalized state vector based on the three source parameters, which is mathematically described as ,in, is the normalized state vector, is the frequency change rate (i.e. the generator terminal voltage frequency change rate, Hz / s), is the maximum frequency change rate of the gas turbine, is the negative sequence current, is the rated current, is the grid voltage, is the terminal voltage, is the rated voltage, is the voltage change rate (i.e. the generator terminal voltage change rate, kV / s), is the maximum allowable voltage change rate, is the phase difference (i.e. the phase angle difference between the generator voltage and the grid voltage), To allow for grid-connected phase difference, is the slip weight (typical value 0.3), is the slip (i.e., the rate of change of phase difference, ° / s), is the maximum allowable slip.

[0022] In this embodiment, outputting the operating condition characteristic matrix based on the normalized state vector and identifying the current dominant operating condition can be specifically implemented by the following steps: S201: Pre-training to obtain weight matrix and feature vector; Specifically: collect historical data sets (100 groups of working condition samples) and input them separately NSVvector, and add one-hot vector labels (such as [0,1,0,0] for frequency-varying conditions); solve with logistic regression Get the weight matrix and the eigenvector .

[0023] S202: Output the operating condition characteristic matrix based on the normalized state vector, the weight matrix, and the characteristic vector, which is mathematically described as: ,in, is the working condition characteristic matrix, is the weight matrix (4×5), is the feature vector (4×1), is the steady-state probability, is the probability of frequency-varying operating conditions, is the probability of grid-connected operation, is the probability of fault condition; S203: Identify the current dominant operating condition based on the operating condition characteristic matrix, that is, identify which operating condition has the highest probability of occurring, and then identify it as the dominant operating condition. Example: , then the frequency-variable working condition is dominant (68%).

[0024] In this embodiment, the optimized control vector is outputted by the normalized state vector and the operating condition characteristic matrix, which can be specifically implemented by the following steps: S301: Determine the control gain matrix through multi-operating condition simulation optimization, specifically: S301-1: Establish a combustion engine model; S301-2: Setting optimization objectives: minimizing grid-connected inrush current and ensuring that the fault clearing time is less than or equal to a preset threshold; S301 - 3 : Particle swarm algorithm is used to solve the optimal matrix as the control gain matrix.

[0025] S302: Obtaining an operating condition intensity coefficient based on the normalized state vector. The operating condition intensity coefficient includes a frequency intensity coefficient, a voltage intensity coefficient, and a phase intensity coefficient. The frequency intensity coefficient is mathematically described as follows: , the voltage intensity coefficient is mathematically described as , the mathematical description of the phase intensity coefficient is ,in, is the first row element of the normalized state vector, is the third row element of the normalized state vector, is the 5th row element of the normalized state vector; S303: Output the optimized control vector based on the control gain matrix, the operating condition characteristic matrix and the operating condition intensity coefficient, which is mathematically described as ,in, is the correction value of the excitation voltage setting value (kV), is the protection action threshold correction coefficient (dimensionless), is the synchronous phase correction angle (°), is the control gain matrix (3×4 matrix, That is, the element in the 1st row and the i-th column of the matrix), is the i-th row element of the working condition characteristic matrix, is the frequency intensity coefficient, is the voltage intensity coefficient, is the phase intensity coefficient.

[0026] In this embodiment, the optimized control vector is converted into execution parameters and dynamic constraints are added, which can be specifically implemented by the following steps: S401: Obtain the excitation voltage setting value based on the excitation voltage setting value correction amount, which is mathematically described as ,in, is the excitation voltage setting value, is the original excitation voltage setting value, To preset the grid connection time, is the current time, Used to smoothly approach the target voltage over time to avoid step disturbances; S402: Obtain the negative sequence current threshold based on the protection action threshold correction coefficient, which can be mathematically described as ,in, is the negative sequence current threshold; S403: Obtain the compensated phase difference based on the synchronous phase correction angle, which is mathematically described as ,in, To compensate for the phase difference, is the original phase difference, is the attenuation factor, the typical value is 2.0, Used to gradually approach the target phase and suppress oscillation.

[0027] In this embodiment, the output dynamic constraint coefficient is used to dynamically constrain the control gain matrix in step S3, which can be specifically implemented by the following steps: S501: Obtaining the execution deviation, which includes a voltage tracking error (i.e., a difference between the excitation voltage setting value obtained by actual monitoring and the excitation voltage setting value obtained in S4), a negative-sequence current tracking error (i.e., a difference between the negative-sequence current threshold value obtained by actual monitoring and the negative-sequence current threshold value obtained in S4), and a phase difference tracking error (i.e., a difference between the compensation phase difference obtained by actual monitoring and the compensation phase difference obtained in S4). S502: Output the dynamic constraint coefficient based on the execution deviation, which is mathematically described as ,in, is the dynamic constraint coefficient, is the voltage tracking error, is the negative sequence current tracking error, is the phase tracking error, is the voltage sensitivity coefficient (typical value is 5.0); S503: Dynamically update the control gain matrix based on the dynamic constraint coefficient and feed it back to step S3, which is mathematically described as ,in, is the updated control gain matrix, This is element-wise multiplication.

[0028] Example 2: A coordinated control system for protection, excitation, and synchronization under multiple operating conditions, including a data integration module, an operating condition identification module, a control optimization module, an execution module, and a dynamic constraint module; The data integration module is used to integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters; The operating condition identification module is used to output an operating condition characteristic matrix based on the normalized state vector and identify the current dominant operating condition; The control optimization module is used to obtain a control gain matrix and output an optimized control vector through the normalized state vector and the operating condition characteristic matrix; The execution module is used to convert the optimized control vector into execution parameters and add dynamic constraints to achieve coordinated control of protection, excitation, and synchronization. The execution parameters include an excitation voltage set value, a negative sequence current threshold, and a compensation phase difference; The dynamic constraint module is used to monitor and feedback the execution deviation in real time, and output the dynamic constraint coefficient for the control gain matrix in the dynamic constraint step S3.

[0029] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A coordinated control method for protection, excitation, and synchronization under multiple working conditions, characterized in that: The following steps are involved: S1: Integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters; S2: Outputting a working condition characteristic matrix based on the normalized state vector and identifying a current dominant working condition; S3: Obtain a control gain matrix, and output an optimized control vector through the normalized state vector and the operating condition characteristic matrix; S4: converting the optimized control vector into execution parameters and adding dynamic constraints, wherein the execution parameters include an excitation voltage set value, a negative sequence current threshold, and a compensation phase difference; S5: Real-time monitoring and feedback of execution deviations, and outputting dynamic constraint coefficients for dynamically constraining the control gain matrix.

2. The coordinated control method for protection, excitation, and synchronization under multiple working conditions according to claim 1 is characterized in that: The step S1 specifically includes: Obtaining the protection system parameters, the excitation system parameters, and the synchronization system parameters, wherein the protection system parameters include the frequency change rate and the negative sequence current, the excitation system parameters include the grid voltage, the terminal voltage, and the voltage change rate, and the synchronization system parameters include the phase difference and the slip; The normalized state vector is output based on the three source parameters, which is mathematically described as ,in, is the normalized state vector, is the frequency change rate, is the maximum frequency change rate of the gas turbine, is the negative sequence current, is the rated current, is the grid voltage, is the terminal voltage, is the rated voltage, is the voltage change rate, is the maximum allowable voltage change rate, is the phase difference, To allow for grid-connected phase difference, is the slip weight, is the slip, is the maximum allowable slip.

3. The coordinated control method for protection, excitation, and synchronization under multiple working conditions according to claim 2 is characterized in that: The step S2 specifically includes: Pre-training obtains weight matrix and feature vector; The working condition characteristic matrix is ​​output based on the normalized state vector, the weight matrix and the characteristic vector, which is mathematically described as: ,in, is the working condition characteristic matrix, is the weight matrix, is the eigenvector, is the steady-state probability, is the probability of frequency-varying operating conditions, is the probability of grid-connected operation, is the probability of fault condition; A current dominant operating condition is identified based on the operating condition characteristic matrix.

4. The coordinated control method for protection, excitation, and synchronization under multiple working conditions according to claim 3 is characterized in that: The step S3 specifically includes: Determine the control gain matrix through multi-operating condition simulation optimization; Acquire an operating condition intensity coefficient based on the normalized state vector, the operating condition intensity coefficient including a frequency intensity coefficient, a voltage intensity coefficient, and a phase intensity coefficient; The optimized control vector is output based on the control gain matrix, the operating condition characteristic matrix and the operating condition intensity coefficient, which is mathematically described as follows: ,in, is the correction value of the excitation voltage setting value, is the protection action threshold correction coefficient, is the synchronous phase correction angle, is the control gain matrix, is the i-th row element of the working condition characteristic matrix, is the frequency intensity coefficient, is the voltage intensity coefficient, is the phase intensity coefficient.

5. The coordinated control method for protection, excitation, and synchronization under multiple working conditions according to claim 4 is characterized in that: The step S4 specifically includes: The excitation voltage setting value is obtained based on the excitation voltage setting value correction amount, which is mathematically described as ,in, is the excitation voltage setting value, is the original excitation voltage setting value, To preset the grid connection time, is the current time; The negative sequence current threshold is obtained based on the protection action threshold correction coefficient, which is mathematically described as ,in, is the negative sequence current threshold; The compensated phase difference is obtained based on the synchronous phase correction angle, which is mathematically described as ,in, To compensate for the phase difference, is the original phase difference, is the attenuation factor.

6. The coordinated control method for protection, excitation, and synchronization under multiple working conditions according to claim 5 is characterized in that: The step S5 specifically includes: Acquiring the execution deviation, where the execution deviation includes a voltage tracking error, a negative sequence current tracking error, and a phase difference tracking error; The dynamic constraint coefficient is output based on the execution deviation, which is mathematically described as ,in, is the dynamic constraint coefficient, is the voltage tracking error, is the negative sequence current tracking error, is the phase tracking error, is the voltage sensitivity coefficient; The control gain matrix is ​​dynamically updated based on the dynamic constraint coefficients, which is mathematically described as ,in, is the updated control gain matrix, This is element-wise multiplication.

7. A coordinated control system for protection, excitation, and synchronization under multiple working conditions, characterized in that: The system is applied to the coordinated control method of protection, excitation, and synchronization under multiple working conditions as described in any one of claims 1 to 6, including a data integration module, a working condition identification module, a control optimization module, an execution module, and a dynamic constraint module; The data integration module is used to integrate three-source parameters, including protection system parameters, excitation system parameters, and synchronization system parameters, and obtain a normalized state vector based on the three-source parameters; The operating condition identification module is used to output an operating condition characteristic matrix based on the normalized state vector and identify the current dominant operating condition; The control optimization module is used to obtain a control gain matrix and output an optimized control vector through the normalized state vector and the operating condition characteristic matrix; The execution module is used to convert the optimized control vector into execution parameters and add dynamic constraints, wherein the execution parameters include an excitation voltage set value, a negative sequence current threshold, and a compensation phase difference; The dynamic constraint module is used to monitor and feedback the execution deviation in real time, and output a dynamic constraint coefficient for dynamically constraining the control gain matrix.

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